As you may recall, one of the judges of MOTHER EARTH NEWS’ Self-Sufficient Food Competition was Dr. Howard T. Odum. And for good reason. Dr. Odum — besides being the kind of good-humored, dynamic guy you just love to have around — has been Professor of Ecology at the University of North Carolina, Chief Scientist for the Puerto Rico Nuclear Center and Director of the Institute for Marine Science of the University of Texas at Port Aransas. He’s also a well-known author of articles and books on energy and the environment and is currently Director of the Center for Wetlands and a Graduate Research Professor at the University of Florida in Gainesville.
Dr. Odum rocked the environmental field in the early ’70s when — at the request of the Royal Swedish Academy of Science — he produced Energy, Ecology, and Economics. This paper outlined the interrelationships of man, his use of energy and the probable future of the planet in far more understandable terms than they’d ever been outlined before. Much of the excellent work now being done by Amory Lovins and other environmentalists would not be getting done — or would be far more difficult to accomplish — if that landmark paper had never been written.
We considered ourselves quite fortunate, then, when Dr. Odum agreed to help judge MOTHER EARTH NEWS’ Food Self-Sufficiency Competition. And we felt even more fortunate when he suggested that one of his students might be interested in running the contest’s winning entry through the now-famous Odum Energy Analysis for us. And that’s exactly what Mike Burnett, whose specialty is alternative agriculture, has done, and here’s Mike’s report.— MOTHER
The Energy Game of the World
As MOTHER EARTH NEWS’ readers are well aware, the old ground rules of the world’s energy game — ridiculously low prices for petroleum, unlimited supplies of natural gas, etc. — have been drastically changed during the past few years. It is very probable that things like the Arab oil embargo and the early-1977 fuel crisis during an unexpectedly cold winter are only the first signs of the far more serious energy concerns that lie ahead.
For this reason, every segment of our society is now being closely examined by the government, special interest groups, environmentalists and just plain concerned citizens. The questions being asked are: “Can this area of human activity function on less energy?” “Can it function on less energy if we somewhat restructure the activity?” “If we do the activity in a completely different way?” “Can we do this job with a different form of energy?” “Can we do away with this job altogether?”
Use of Energy in the Agriculture Business
U.S. agriculture — which produces a very large percentage of the world’s food and natural fibers — seems to have become especially energy intensive during the last 30 or 40 years. In particular, its current dependence on fossil fuels is enormous: Fossil fuels power its tractors, combines and other equipment in the field … the dryers that must be used to cure its fragile modern hybrid grains … the trucks which haul its crops to market … the machinery which processes and packages those crops … the trucks, trains and other forms of transportation that distribute the packaged products … and all the manufacturing processes which fabricate those trucks, tractors, combines, etc., themselves.
To say nothing of the vast amounts of fossil fuels that go into the production of chemical fertilizers, pesticides, herbicides, preservatives, extenders, flavorings, colorings, packaging, etc., now used by the agribiz food and fibers industry. Or the additional fossil fuels wasted in cleaning up the air, water and land polluted by the use of these same fertilizers, pesticides, packages, etc. Or the fossil fuels burned to operate a large segment of society’s health establishment; a segment that would probably be entirely unnecessary if our population were not exposed to the steadily increasing load of chemicals, preservatives, extenders, etc., that is routinely pumped into its food, the air it breathes, the water it drinks, etc. And so on and on.
The Answer: Redesign
Is there any way to break this escalating agribiz gluttony for fossil fuels? Yes, there is. Redesign — by reaching both back into the past and forward into the future — the production of food and fiber so that it needs less instead of steadily increasing quantities of fossil fuels. Reverse the rapidly accelerating trend toward centralized, big, fossil-fuel-based, “state of the art” agribusiness. Decentralize farming. Put it back into the hands of people who care, instead of corporations and managers who operate only for a profit. Scale agriculture down. Introduce more intermediate technologies. Make farming less dependent on fossil fuels and more dependent on solar-driven natural energies (which, after all, must ultimately sustain society anyway when the fossil fuels are all depleted). And start doing it now while the change can still be made relatively easily, instead of later when it may not be possible to make such changes at all.
OK. How do we begin this massive undertaking? Obviously, by defining the problem. By inventing and organizing and refining a set of tools that can help us figure out where we now stand and what we must do to get to where we’d like to be.
One of the best of those tools so far invented is the Energy Analysis devised by Dr. Howard T. Odum. I have applied Dr. Odum’s methods to a study of the Dan Taylor family’s Arkansas farm, which was the first-place winner in MOTHER EARTH NEWS’ Food Self-Sufficiency Competition. Some of the results were quite interesting.
In conducting one of these studies, we make use of energy flow diagrams that graphically represent the system being examined. This helps us to comprehend highly complex systems and to discover relationships we otherwise might have overlooked.
The drawing that accompanies this article in the Image Gallery illustrates the energy flow that takes place on the Taylor farm. This is a simplification (a “mini-model”) of a much more detailed diagram that I have developed, but it contains everything we’ll need to introduce you to Dr. Odum’s concept and to explain the basic operation of the Taylor farm.
(Note: Click on the Image Gallery link above to see the diagram Mike Burnett made for the Dan Taylor Family’s Ozark farm.)
The double lines on the diagram represent the boundaries of the system (the farm). The symbols represent various things (the sun, land, plants, animals, people, equipment, etc.) both inside and outside the system (on and off the farm). The solid lines which connect these symbols indicate energy flows and the dotted line represents the flow of money.
As we can quickly see, energy flows into the Taylor system from two main sources (the sun and the land, both represented by circles) and from exchanges made with the main economy. We also see that energy flows out of the system in the form of goods produced (in this case, animals … cattle and hogs) and in the form of degraded energy (depreciation and waste heat). The heat sink symbol on the lower right represents the total of all depreciation on equipment, tools and buildings combined with the waste heat generated by the respiration of the system’s plants, animals and people plus the friction and other inefficiencies inherent in any energy transformation process.
Flow of Energy
Obviously, the total amount of energy flowing into the system must equal the amount flowing out. This is the first law of energetics (thermodynamics), which states that energy can neither be created nor destroyed.
The degraded energy shown on the diagram (the energy that flows down into the sink at the drawing’s lower right) just as surely represents the second law of thermodynamics. Which states that in any energy-transforming (work-performing) process, potential energy is degraded into a form that is no longer able to do work. This is also known as the law of increasing entropy (where “entropy” is a scientific word for disorder).
Our system contains several energy modules within its boundaries. A bullet-shaped module represents a producer, such as a plant or — in a larger sense — the raw Taylor farm itself. A hexagon-shaped module indicates a consumer, such as an animal or a person (in larger studies, a major consumer is often a city). Each of these modules is attached to the heat sink: this represents the metabolism of the organism.
The water tank-shaped (round on the bottom, pointed on top) modules indicate a storage of some material … such as biomass, buildings or money. They, too, connect to the heat sink, which represents their depreciation with time.
The pointed box modules represent interactions between two other modules. Their connections to the heat sink show that the energy of two interacting flows cannot produce work at 100 percent efficiency, which would defy the second law of thermodynamics.
The rectangular box symbolizes a sub-unit; in this case, the farm structures, equipment and the work done by the Taylors with such tools. The diamond-shaped modules between the Taylor farm and the main economy represent the exchange of money for goods and services (other forms of energy). Notice, when such exchanges are made, that money quite obviously flows in the opposite direction of energy.
Now when we look at the Taylor farm’s energy flow diagram, we can immediately see the energy sources which keep the system running. And the major source, of course, is the sun: Nearly one trillion kilocalories of sunlight fall on the Taylors’ 160 acres annually. This is by far the largest energy flow on the diagram.
It will help to put that one trillion kilocalories into meaningful terms if you know that a typical individual in our society eats only about one million kcal (one thousand-thousandth of a trillion kcal) each year.
People, however (vitamin D aside), can’t really eat sunlight. We must rely on plants to convert it into some form of biomass that we can consume or that we can feed to animals and let them convert into protein and fats for us.
In the case of the Taylor farm, its 30 acres of pasture annually produce about 875 million kcal of biomass. Of this, about 150 million are consumed by animals. And the animals, in turn, produce a total of approximately 13.3 million kcal of food … part of which is consumed on the homestead and part of which is sold.
When it comes to directly converting their feed to food, then, the animals in this system are only about 8 percent efficient. That, however, is not as bad as it sounds. Because those animals are converting mostly human-inedible feeds into high-quality protein. Furthermore, the Taylors’ team of oxen contribute nearly as much muscle power to the homestead’s operation as do the people living there. And all the animals on the farm produce manure, a valuable resource that is frequently overlooked these days.
The annual energy equivalent of the manure produced on the Taylor farm amounts to a substantial 31.7 million kcal which is the energy equivalent of all the food you’ll eat during a third or more of your lifetime. Or to put it another way, there is over twice as much energy in the Taylor animals’ manure as there is in the meat, milk, eggs, etc., produced by those animals. No wonder this natural soil builder is such a valuable product (and isn’t it a shame that manure is so often considered a nuisance and a waste on the “modern” agribiz operation?).
Nor can we overlook the fact that it is animal produce the Taylors sell to support their homestead’s modest $2,900 annual budget. Their farm animals, especially the cattle and hogs, contribute to the success and stability of the homestead in many ways. The livestock’s importance may become even more pronounced if, as the Taylors hope, they’re eventually able to substitute four tons of chestnuts a year (from trees they’ve planted) for the pig feed they now purchase. If that dream is realized, their farm will take another giant step toward total self-sufficiency. [EDITOR’S NOTE: There’s obviously far more to an animal’s “efficiency” than the narrow view taken by Diet for a Small Planet.]
A hardworking homesteader eats more than most folks (and doesn’t mind recycling some of the food he or she has grown through the compost pile). The four Taylors consume a total of approximately six million kcal of food a year. Their three-acre garden supplies the largest percentage of this input, milk and milk products are next, and grains and meat together add up to slightly less of the family’s total diet than the milk and milk products they consume. This could be interpreted as another vote in favor of at least one homestead animal: the family milk cow.
About half of the food energy consumed by the Taylors goes back into the system in the form of farmwork. They do more work than even their oxen. And in addition to human and animal input, work on the Taylor homestead consumes 3.7 million kcal of burned wood every year and 13.4 million kcal of purchased fossil fuels. The amount of purchased energy should be drastically reduced once the family has its woodburning steam-powered generators up and running.
As things now stand (even without the steam engines), however, the Taylors have done an impressive job of reducing their fossil fuel energy consumption. As noted, they purchase only about $2,900 worth of goods and services from the main economy each year. And each dollar that they or any one of us now spends in that economy represents roughly 19,000 kcal of fossil fuel energy. Which means that the family is dependent on the main economy for 55.1 million kcal of coal equivalents (CE).
Energy Analysis of a ‘Typical’ U.S. Family
How does that compare to a “typical” U.S. family? Well, on the average, fossil fuel energy equivalent to 12 tons of coal is burned each year to support each man, woman and child living in this country. The Taylors, on the other hand, require only 1 3/4 tons of coal consumption for each member of their family. Which means that they need only 15 percent of the average to support their way of life! When it comes to fossil fuel energy consumption, the Taylors are living 6.6 times more lightly on the earth than the average American family of four!
All in all, then, the Taylors have done quite a job of building a domesticated ecosystem with energy flows that, in many respects, parallel the energy flows of a natural ecosystem.
Energy from both natural and fossil fuel sources flows through their homestead and is degraded into waste heat. Materials cycle around their system’s loops, driven by that flow of energy. Sunlight is captured by plants … some of which (trees) are burned, some of which (garden and other crops) are eaten by the family and some of which (pasture and crops) are converted into high-quality protein by the farm’s animals.
Some of the animal products, in turn, are eaten right on the homestead. Most are exchanged for tools, equipment and other things which are better produced off the homestead. (Most of the equipment purchased by the Taylors is used to augment and direct the farm’s natural energy flows.) And finally, the recycling of their animals’ manure by the family completes a loop that is vital in nature but often neglected in modern industrial societies.
In short, by directing interaction of their farm’s natural energies with purchased fossil fuel-derived inputs (fuels, tools, etc.), the Taylors are able to live in a nearly self-sufficient manner. And, as they realize more of their goals in the years ahead, the family’s energy umbilical cord will become even thinner than it is now.
We might all do well to emulate the Taylors. As rising fuel costs and increasing fossil fuel scarcities disrupt more and more lives in the coming years, the Taylors’ lives will hardly be affected at all.